Storage container

ABSTRACT

A rectangular carton for storing packages of polymer, which carton is divided by intersecting partitions into four rectangular cells with each cell sized to hold snugly a single stack of such packages. The carton prevents bursting of the packages due to cold flow of the polymer during storage and shipping.

United States Patent 41,23 A,23 B, 23 BT;220/1l3 [56] References CitedUNITED STATES PATENTS 1,971,863 8/1934 Lupton 229/15 2,411,144 11/1946Bergstein.... 229/28 UX 2,539,304 l/195l Hall et al. 229/28 2,539,966 1/1951 Orovig 229/28 UX 3,248,037 4/1966 Simkins 229/15 PrimaryExfiminer.loseph R. Leclair Assistant Examiner-James R. GarrettAttorney-Raymond E. Blomstedt ABSTRACT: A rectangular carton for storingpackages of polymer, which carton is divided by intersecting partitionsinto four rectangular cells with each cell sized to hold snugly a singlestack of such packages. The carton prevents bursting of the packages dueto cold flow of the polymer during storage and shipping.

PATENTED new I971 3.628.718

FIG.3

FIGJ FI6.2 Q

INVENTOR BEN L. BROY LES ATTORNEY STORAGE CONTAINER THE INVENTIONSynthetic elastomers such as butadiene/styrene polymers (SBR) andethylene/propylene/diene polymers (EPDM) are normally stored and shippedin plastic or paper wrappings or bags containing about 34 kg. of polymereach. These packages, when freshly filled, normally have dimensions ofabout l8X35X70 cm. in the case of SBR and l8X4lX6l cm. for EPDM but uponstorage and/or shipping the polymer tends to settle or cold-flow to suchan extent that even under normal conditions of storage and handling thepackages are frequently subjected to pressures exceeding their strength,resulting in bursting of the packages with resultant loss orcontamination of polymer and the expense of recovery or replacementthereof. This difficulty is increased when the packages are stacked oneupon the other on pallets and the pallets are tiered with other pallets.With certain polymers a single stack of five packages can produceexceedingly high pressures on the bottom container and bursting iscommonplace even under normal storage and shipping conditions.

One solution to this problem has been to place such stacks ofpolymer-filled packages into close-fitting heavy wood boxes to restrainexpansion of the packages during handling and shipping. This ispractically prohibitively expensive due to the high cost of wood boxesas well as the labor cost in assembling them and the relatively heavyweight in handling and shipping. There has been a need for a cheap,easily assembled disposable, collapsible carton which would solve theshipping and storage problems associated with cold flow of elastomericpolymers.

In accordance with this invention there is provided a container forstoring and shipping packaged materials which are subject to settling,expansion, or cold flow. This container is a rectangular box or cartonof cardboard, corrugated paperboard or other suitable, flexible, cheapsheet material, divided by vertical partitions into at least four cellsor compartments similar in cross section to and equal in height to thebox. The term rectangular" as applied herein to a three-dimensionalstructure such as a box, container or cell, refers to a right parallelpiped, that is, a six-sided container with planar faces of which eachface is in the form of a rectangle. This box is cheap enough to bediscarded after use and is easily made from corrugated paperboard byfirst folding four sheets of paperboard to fonn four individual tubes oropen-ended cells having unifonn rectangular cross sections with edgescorresponding to the dimensions of the two largest edges of the packagesto be contained therein. The four tubes are then arranged vertically inabutting contact about a central axis to form a four-celled carton inthe four quadrants about the axis and having the same overall height andrectangular cross-sectional configuration as the individual cells. Thelarger external faces of the cells in contact with each other arefastened together, as by rivets or suitable adhesive, and each of thetwo larger sidewalls of the four-celled carton thus formed, isreinforced by covering with an adhering sheet of material. Theindividual cells can be made with fold tabs or flaps at one end or bothas desired to permit closing of one or both ends of each cell in thesame manner as a conventional corrugated paperboard box or shippingcontainer. Such flaps contribute strength and rigidity to the structure.In a preferred embodiment one end of each of the cells does have theseend flaps and in assembling the four tubes to form a carton these areplaced to form the bottom of the carton.

The bottom of the carton is then capped by a removable tray ofpaperboard having sidewalls which extend up the outside walls of thecarton preferably at least percent of the height but in any eventsufficiently to provide close-fitting support for the base of the cartonand part of the walls.

The carton is then ready for filling with packages of polymer and in apreferred embodiment each cell of the carton is of a size to receive aseven-bag stack of polymer laid face to face; the face of the bag beingthe largest flat surface thereof. Naturally it is important that thecross section of the cell be of suffrcient size to permit insertion ofthe bags with reasonable ease but yet small enough to provide asufficiently snug fit so that the expansion of the bags due to cold flowof polymer is restrained at least to the extent of preventing burstingof the bags.

Experience appears to indicate that a four-celled carton is much moreeffective in preventing bag bursting due to cold flow than any otherconfiguration. This may be due to support provided at the central axisof the box where all four cells meet. In any event this particularconfiguration even with a material as weak as corrugated paperboard iseffective to prevent bag bursting due to cold flow of polymer.

The invention can be more easily understood by referring to the drawingswhich show sequential steps for constructing a carton of the presentinvention. In the drawings FIG. 1 shows a sheet of cardboard ll creasedand folded preparatory to forming the rectangular tube of FIG. 2 havingtaped joint 15 which bisects one face of the tube, although it can becloser to either side as desired. In this particular embodiment the tubeis made with end flaps 12. Four such tubes are made and assembled toproduce the four-celled carton shown in FIG. 3, adhesive first beingapplied to the larger contacting outside faces 13 of the tubes so thatthese faces will be adhered to each other. Other fastening means canalso be used and it is not necessary that the faces be fastened overtheir entire contacting area. It will be noted that for ease of assemblyand carton strength the four tubes are assembled so that the taped jointin each tube is displaced from that in the adjacent tube either by beingon opposite sides of a tube, as shown, or by being staggered. Coversheets 14 are then fastened by convenient means, preferably by adhesive,to opposite faces of the carton to provide support and to hold the cellsin place. End flaps 12 are closed as shown in FIG. 4 and the bottom ofthe carton is capped by tray 17 formed from another sheet of cardboardin conventional manner and having sidewalls 16 which after cappingextend partially up the outside walls of the carton. After the cells ofthe carton are filled with a stack of polymer-loaded packages, the topof the carton is capped with a cover which can be the same as the bottomtray 17. FIG. 5 shows how such a fourcelled carton with end flaps can becollapsed for shipping or storage without excessive use of space. FIG. 5shows the unit partially collapsed and FIG. 6 in a more completelycollapsed state. The arrangement of the four cells and the manner offastening them together pennits the carton to be readily collapsed forstorage and shipping and, being in one piece except for top and bottom,can be readily set up. The carton can be collapsed completely until itsthickness is merely that of the layers of sheet material present. FIG. 7shows a sheet of cardboard creased and ready for folding to form a topor bottom cover for capping the four-celled carton.

In normal use neither the top nor bottom of the carton need be adhered,riveted, or otherwise fastened to the body of the carton althoughnormally, prior to shipping, the top and bottom are strapped to the boxby conventional shipping straps.

Any suitable sheet material can be utilized to make the container of thepresent invention but corrugated cardboard or paperboard are eminentlysuitable and probably is the cheapest practical type of material forthis use. Any sheet material which can be folded as indicated and hassufficient rigidity to provide the necessary support can be used. Filmsand fabrics of synthetic and natural sheet materials can be used ifdesired for all or part of the structure depending upon the particularefi'ect desired. Similarly any suitable adhesive can be used so long asthe desired strength is provided. Adhesive is normally applied only tocover sheets 14 and to the external large contacting faces of theconduits during assembly but when greater strength is desired adhesivesmay also be applied to the smaller contacting faces of the tubes duringtheir assembly if collapse of the structure is not necessary prior touse. Also the top and bottom covers of the carton may be adhered to thebody portion to provide greater strength but this has not been found tobe necessary for normal usage.

Although adhesives are normally used where indicated above because ofconvenience, cheapness, and strength, any convenient fastening means canbe used including staples, rivets, or interlocking structures built intoor added to the walls to be attached.

in order to test a carton of this invention with respect to itseffectiveness in preventing bag bursting due to cold flow ofethylene/propylene/ 1,4-hexadiene terpolymer a carton such as describedwas constructed entirely of 158 kg. double-wall corrugated paperboard.After folding in the bottom flaps and capping the bottom with apaperboard tray as described, each cell was loaded with 238 kg. of 40Mooney polymer, the polymer being in polyethylene bags each containing34 kg. of polymer. Thus there was a stack of seven bags of polymer ineach cell. The filled carton was capped with a top cover and arectangular wood pallet holding four stacks of bagged polymer weighing atotal of 1,035 kg. was placed on top of the filled carton. The containerwas stored in a warehouse at about 23 C. for about 20 days and thenshipped a distance of 1,800 miles by truck under the same conditions. Itwas found that the filled carton and the individual bags of polymerwithin it were held in practically their original shape by the cartonand were in good condition showing very little evidence of deformation.A similar carton tested under the same conditions was equally successfulin preventing bag damage.

lclaim:

l. A lightweight carton for storing and shipping packaged materialswhich are subject to settling or flow, said carton comprising a. fourrectangular cells assembled in abutting relationship in the quadrantsabout a central vertical axis to form a four-celled carton having thesame rectangular cross-sectional configuration and height as theindividual cells,

b. one outer face only of each cell being fastened to the abutting outerface of an adjoining cell,

c. each of the sidewalls of the carton which are parallel to thefastened cell wall faces, being covered by a sheet material fastenedthereto, and

d. the top and bottom of the carton being capped by removable coverswhich extend partially down the outer walls of the carton.

2. The carton of claim 1 in which the larger contacting outer 5 faces ofadjoining cells are fastened together.

3. A four-compartment container assembly comprising four tubularcontainer subassemblies each of rectangular cross section each havingtwo side panels and two end panels with said panels carryingbottom-forming flaps;

a first two of said container subassemblies being joined together intransverse aligned relation at a single side panel to form a first pairof joined container subassemblies;

a second two of said container subassemblies also being joined togetherin transverse aligned relation at a single side panel to form a secondpair of joined container sub assemblies;

said first and second pairs being arranged to form an array in which endpanels of the subassemblies of one pair are in adjacent opposed relationto end panels of the subassemblies of the other pair with thesubassemblies of one pair in longitudinal alignment with thesubassemblies of the other pair;

a rigid reinforcing panel secured on each of the two opposite sides ofthe array to the outer faces of the aligned subassembly side panels;

the two remote subassembly end panels of the array being exposed andforming the end faces of the container assembly,

the adjacent and facing end panels of the container subassemblies beingunattached and capable of being separated to form a diamond'shapedconfiguration and the opposite exposed subassembly end panels forming anangular configuration with the apices of the configuration extendingoutwardl from the center of the assembly as said reinforcing pane s aremoved toward each other to collapse said four-compai1ment container andprovide a substantially flat contour for the collapsed container.

1. A lightweight carton for storing and shipping packaged materialswhich are subject to settling or flow, said carton comprising a. fourrectangular cells assembled in abutting relationship in the quadrantsabout a central vertical axis to form a fourcelled carton having thesame rectangular cross-sectional configuration and height as theindividual cells, b. one outer face only of each cell being fastened tothe abutting outer face of an adjoining cell, c. each of the sidewallsof the carton which are parallel to the fastened cell wall faces, beingcovered by a sheet material fastened thereto, and d. the top and bottomof the carton being capped by removable covers which extend partiallydown the outer walls of the carton.
 2. The carton of claim 1 in whichthe larger contacting outer faces of adjoining cells are fastenedtogether.
 3. A four-compartment container assembly comprising fourtubular container subassemblies each of rectangular cross section eachhaving two side panels and two end panels with said panels carryingbottom-forming flaps; a first two of said container subassemblies beingjoined together in transverse aligned relation at a single side panel toform a first pair of joined container subassemblies; a second two ofsaid container subassemblies also being joined together in transversealigned relation at a single side panel to form a second pair of joinedcontainer subassemblies; said first and second pairs being arranged toform an array in which end panels of the subassemblies of one pair arein adjacent opposed relation to end panels of the subassemblies of theother pair with the subassemblies of one pair in longitudinal alignmentwith the subassemblies of the other pair; a rigid reinforcing panelsecured on each of the two opposite sides of the array to the outerfaces of the aligned subassembly side panels; the two remote subassemblyend panels of the array being exposed and forming the end faces of thecontainer assembly, the adjacent and facing end panels of the containersubassemblies being unattached and capable of being separated to form adiamond-shaped configuration and the opposite exposed subassembly endpanels forming an angular configuration with the apices of theconfiguration extending outwardly from the center of the assembly assaid reinforcing panels are moved toward each other to collapse saidfour-compartment container and provide a substantially flat contour forthe collapsed container.